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Structural Issues (structural + issues)
Selected AbstractsA focusing Laue diffractometer for the investigation of bulk crystalsJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2008Matthias Stockmeier A focusing Laue diffractometer for high-energy X-rays of up to 300,keV in a laboratory environment is presented. The long attenuation length for X-ray energies above 50,keV allows for the non-destructive investigation of structural issues and bulk properties of single crystals. Furthermore, massive sample environments such as high-temperature furnaces can be used more easily. With an area detector, anisotropic mosaicities or crystallite structure become visible without any rocking movement of the sample. [source] Single-molecule analysis of chromatin: Changing the view of genomes one molecule at a timeJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2008Santhi Pondugula Abstract Wrapping DNA into chromatin provides a wealth of regulatory mechanisms that ensure normal growth and development in eukaryotes. Our understanding of chromatin structure, including nucleosomes and non-histone protein,DNA interactions, has benefited immensely from nuclease and chemical digestion techniques. DNA-bound proteins, such as histones or site-specific factors, protect DNA against nuclease cleavage and generate large nucleosomal or small regulatory factor footprints. Chromatin subject to distinct modes of regulation often coincides with sites of nuclease hypersensitivity or nucleosome positioning. An inherent limitation of cleavage-based analyses has been the inability to reliably analyze regions of interest when levels of digestion depart from single-hit kinetics. Moreover, cleavage-based techniques provide views that are averaged over all the molecules in a sample population. Therefore, in cases of occupancy of multiple regulatory elements by factors, one cannot define whether the factors are bound to the same or different molecules in the population. The recent development of DNA methyltransferase-based, single-molecule MAP-IT technology overcomes limitations of ensemble approaches and has opened numerous new avenues in chromatin research. Here, we review the strengths, limitations, applications and future prospects of MAP-IT ranging from structural issues to mechanistic questions in eukaryotic chromatin regulation. J. Cell. Biochem. 105: 330,337, 2008. © 2008 Wiley-Liss, Inc. [source] The tenth anniversary of Suzuki polycondensation (SPC)JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2001A. D. Schlüter Abstract This article describes the successful transfer of the Suzuki cross-coupling (SCC) reaction to polymer synthesis, one of the major developments within the last decade of polymer synthesis. The polymers prepared by Suzuki polycondensation (SPC) and its Ni-catalyzed reductive counterpart are soluble and processable poly(arylene)s that, because of their rigid and conjugated backbones, are of interest for the materials sciences. Achievable molar masses easily compete with those of traditional polyesters and polyamides. This article also provides insight into some synthetic problems associated with the transfer of SCC from low molar mass organic chemistry to high molar mass polymer chemistry by addressing issues such as monomer purity, stoichiometric balance, achievable molar masses, and defects in the polymer structure. Although the emphasis of this article is synthetic and structural issues, some potential applications of the polyarylenes obtained are briefly mentioned. Together with the enormous developments in the areas of metallocene, ring-opening metathesis, and acyclic diene metathesis polymerization, the success of SPC impressingly underlines the increasing importance of transition-metal-catalyzed CC-bond-forming reactions in polymer synthesis. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1533,1556, 2001 [source] Constraints and blocks to change and improvement on acute psychiatric wards , lessons from the City Nurses projectJOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 5 2006G. BRENNAN rmn rnmh ba(hons) Recent years have seen sustained criticism and inspection of acute inpatient psychiatric wards, with the publication of reports and research leading to policy developments and a variety of efforts to improve perceived deficits. The City Nurses project seeks to reduce levels of conflict and containment on acute wards through the placement of expert nurses on wards to assist with the implementation of changes according to a working model of conflict and containment generation, based on previous research. Evaluation has shown significant decreases in aggression, absconding and self-harm by patients. However, in the course of working with the wards, various constraints and blocks to change have been identified and we describe these in detail in this paper. Analysis of the fieldwork diaries of the two City Nurses identified that change was hindered by limited staffing resources, problems with the physical environment and other resources, insufficient beds and the process of bed management, hierarchical ambiguity and multidisciplinary issues, the overdemanding role of the ward manager, and pervasive anxiety about the potential for serious untoward incidents and their implications for staff. We argue that sustained positive change in acute inpatient psychiatry requires these underlying structural issues to be both acknowledged and, if possible, resolved. [source] "Too many theories and not enough instruction": perceptions of preservice teacher preparation for literacy teaching in Australian schoolsLITERACY, Issue 2 2006William Louden Abstract In this paper, we describe part of an Australian national research project that aimed to find out how well prepared beginning teachers are to teach literacy. A majority of beginning teachers participating in a series of national surveys and focus group meetings were confident about their personal literacy skills, their conceptual understandings of literacy, their understanding of curriculum documents and assessment strategies and their broad preparation to teach. Fewer beginning teachers were confident about their capacity to teach specific aspects of literacy such as viewing, spelling, grammar and phonics, or about their capacity to meet the challenges of student diversity. Senior staff working with beginning teachers were generally sceptical about the quality of teacher preparation for teaching literacy and were less confident than the beginning teachers about personal literacy skills. We discuss these findings in relation to the relative importance placed on particular substantive and structural issues by the study participants and in terms of previous findings. [source] Organizational Identity and the Structure of Nonprofit Umbrella AssociationsNONPROFIT MANAGEMENT & LEADERSHIP, Issue 3 2001Dennis R. Young This article applies the concept of organizational identity to the structural issues faced by national and international nonprofit umbrella associations. Such associations grapple with several possible self-concepts, including goal-seeking systems, economies, and polities . Two associations,CIVICUS and Girls Incorporated,are studied in depth. Consensus around aclear identity is found to be a key factor in resolving the structural dilemmas of these associations. [source] Flavin-based Blue-light Photosensors: A Photobiophysics UpdatePHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 6 2007Aba Losi This review deals with the biophysical aspects of flavin-based photosensors, comprising cryptochromes, LOV (Light, Oxygen and Voltage) and BLUF (Blue Light sensing Using FAD) proteins. Special emphasis is given to structural issues, photocycle quantum yields and energetics, mechanism of the light-triggered reactions, early stages in signal transduction and oligomeric states of the light sensing protein modules. For BLUF and LOV domains important parallels are emerging, despite their different ,/, fold arrangement, whereas there is increasing evidence for a mechanicistic and functional splitting of the cryptochrome family. [source] | ||||||||||